Search Results

Vibrations analysis methods are common as fault detection and diagnosis tools for rotating machines. The successful implementation of this method in various maintenance programs motivates its application to the class of SI engines. In this work, our goals in applying the method are to provide alerts for abnormal operation, to enable detection of the source of the abnormality, and to provide the means to estimate the severity of malfunctions evolving in the engine. Experiments were performed with a four-stroke, four-cylinder in-line, carbureted SI engine. The vibrations were measured at two points around the rear crankshaft bearings in addition to two opposing points on the sides of the engine-block. At each point the vibrations were measured along the axial, the radial and the tangential directions relative to the crankshaft axis.

Advanced engine maintenance programs incorporate various methods for monitoring the engine parts so as to be able to foresee malfunctions and interruptions of normal operation. The present study is concerned with the development of a vibration signature analysis method for early fault detection and diagnosis in internal combustion engines. The successful implementation of this simple and straightforward method in many maintenance programs motivates the application of this method to the class of SI engines. An acceleration transducer is mounted on the engine and the vibration signals are recorded during the engine operation. The measurements are then transformed to the frequency domain where the frequencies and the amplitudes of the harmonic components of the vibrations waveform are analyzed and compared to the corresponding vibration signature under normal operation conditions.